Relief-valve.



Patented July l6, l90l.

. M. D. LARKIN.

' RELIEF VALVE.

(Application filed Nov. 17, 1900.) (lo lludol.)

INVENTOR Qa/ZZZZZLQW'IL R w mun no imurn'a, wmmmu. n. c.

UNITED STATES PATENT OFFICE.

MAURICE D. LARKIN, on DAYTON,VOHIO.

\ RELIEF-VALVE.

SPECIFICATION forming part of Letters Patent N 0. 678,405, dated July 1 6, 1901. Application filed November 17, 1900. Serial No. 36,899. (No model.)

To all whom it may concern:

Be it known that I, MAURICE D. LARKIN, a citizen of the United States, residing at Dayton, in the county of Montgomery, State of Ohio, have invented certain new and useful Improvements in Relief-Valves, of which the following is a specification, reference being had therein to the accompanying drawings.

This invention relates to relief-valves for use in connection with liquid-conducting lines wherein the liquid is transmitted under pres sure, particularly fire-extinguishing apparatus.

Theinvention has for one object to improve the structure disclosed in Patent No 6(lf i,0 5,3, granted June 21, 1898,-t L. O. Dehnel, so as to insure the quick and positive operation of the relief-valve when the pressure in the line is increased by closing the escape-outlet and also to permit a free discharge of the liquid under pressure through the valve.

A further object of the invention is to provide a structure of flap-valve which when not in use will leave the passage through the easing free from obstruction and when raised will have sufiicient throw to effect the relief operation. g

A further object is to provide a construction of piston and cylinder which will when in one position effect a full and free dis charge of the liquid under pressure and in the opposite position effectually prevent such escape when the outlet from the line is opened.

Other objects and advantages of the invention will hereinafter appear in the following description, and the novel features thereof Will be particularly pointed out in the appended claims. 1

Referring to the drawings, Figure 1 is a vertical section through the valve; Fig. 2, an end elevation'of the same with the relief con ducting-pipe removed. Fig. 3 is a perspec-' tive of the flap-valve, and Fig. 4 is a similar view of the piston-casting.

Like letters of reference indicate like parts in the several figures of the drawings.

The letter A indicates the valvecasing, which is provided at opposite ends with suitable screw-threads for attachment 'to' hose, pipes, or other liquid-conducting lines. It will be understood that this valve is ordinarily applied between the engine, hydrant, or other source of pressure and the conducting hose or line, so as to prevent the bursting of the latter when the outlet therefrom is closed and the pressure therein consequently greatly'increased. This casing is provided with arelief-port A and valve seat or pocket A adapted to receive and contain a flapvalve B. The relief-port is formed with a cylinder 0, having at its outer op'en'end a series of guide-fingers O,spa"ced from each other to permit the free discharge of water between the same. Suitably connected to the relief A is a relief conducting-pipe A which receives the discharge'from the cylinder C. Within the cylindera piston D is 10- cated"and provided with a stem D, having upon one side a series of rack-teeth D and upon the opposite face a guide-rib D y-by which means a straight and accurate movement of the piston is insured within the cylinder. This structure also insures the easy movement of the piston and obviates the necessity of using any adjusting devices therefor. The flap-"alve B is pivoted within the casing by means of a pin or bolt B, and upon its hub is formed a series of rack-teeth B adapted to mesh with those upon the valvestem D. The flap-valve is suitably curved in cross-section and at its free end B to conform to the curvature of the casing and the seat A therein.

In order to effect a free and easy movement of the flap-valve, an enlarged path or way A is "provided in the cas- 'ing to the extent of the travel of the flapvalve. The curved sides 13 of this valve serve to distribute the pressure thereon and direct the liquid therefrom, so as to permit a movement of the valve through a body of liquid under pressure without difficulty.

In the operation of the invention when the flap-valve B is lying in the position shown by d tted lines in Fig. 1 the water or liquid hasmassage through the casing, as the valve is located within the seat A and o ders no obstruction thereto. At this timethe piston is disposed within the cylinder, so-as to close the outlet-portsbetween the'guides C. Now if the outlet from the hose or pipe be closed and the pressure upon the liquid continues the increase within the pipe or hose is very-rapid and tends to burst the same.

Under these conditions this pressure is transmitted to the piston D and the same forced outward from the cylinder, thus permitting the water under pressure to be-discharged between the guides and around the piston. These guides extend to the full limit of movement of the piston, and thereby prevent the packing-ring thereof from expanding and catching on the edge of the cylinder, while the rib upon the piston-stem forms a true and continuous guide for its movement and maintains the rack-teeth in proper alinement with the teeth upon the flap-valve. As soon as the outlet from the hose is opened the pressure of the water acts upon the surface of the flap-valve and by reason of its area forces it to its seat, thus returning the piston to the cylinder and closing the relief-port. The present structure of valve permits a greater travel than heretofore, and therefore causes a quicker action of the parts and a full closing of the relief. Under previous construct-ions of relief-valves when the outlet was closed the pressure within the hose increased from twenty to forty pounds, while with the present construction of flap-valve and relief-port the maximum increase does not exceed five pounds.

It will be obvious that changes may be made in the details of construction and configuration of the several parts without departing from the spirit of the invention as defined by the appended claims.

The use of the curved valve and case presents an important improvement in this art, as it prevents the escape of water around the edges of the flap-valve. The curved end B of the flap-valve corresponds to the shape of the case,thus effecting a close fit between the valve and case to prevent the passage of water around the valve. The curved body of the flap-valve adapts the same to rest in the recess of the case without oifering any obstruction to the passage of water. The curved form also permits a much longer travel than heretofore, thus increasing the movement of the relief-piston,and facilitates the escape of a larger amount of water through the port. The close fit of the valve causes the same to quickly operate under all conditions.

\Vliile this invention has been described in its relations to prevent the bursting of hose, still it may be applied to prevent damage to machinery, engines, hydrants, pumps, and any class of devices wherein a moving body of liquid or vapor is used under pressure.

Having described my invention and set forth its merits, what I claim, and desire to secure by Letters Patent, is-

1. A relief-valve comprising a casing, a relief-port therein, a piston in said port, a stem from said piston having at opposite points rack-teeth and a longitudinally-extending guide-rib engaging the casing, and a flapvalve pivoted in the casing and provided with teeth to engage those upon said stem, substantially as specified.

2. A relief-valve comprising a casing, a cylindrical relief-port having an open end, a piston adapted to travel within and beyond the end of said port, a stem from said piston provided with a guide-rib and rack-teeth thereon, and a flap-valve pivoted within the casing and provided with means to engage the, teeth upon said stem, substantially as specified.

3. A relief-valve comprising a casing, a cylindrical relief-port having an open end and guide-fingers extended beyond the body portion thereof, a piston in said port adapted to travel over said fingers, a stem from said pis ton provided with rack-teeth, and a flap-valve pivoted within the casing and provided with means to engage said teeth, substantially as specified.

4. A relief-valve comprising a casing provided with a seat in its wall, a relief-port for said casing, a piston in said port, a flap-valve curved to fit said seat, and means for connecting said valve and piston, substantially as specified.

5. A relief-valve comprising a casing, a relief-port therein, a piston in said port, a stem from said piston having upon one face a longitudinal guide-rib and upon the opposite face a series of rack-teeth, and a valve within the casing adapted to mesh with said teeth and operate said stem, substantially as specified.

6. A relief-valve comprising a casing, a cylindrical relief-port having spaced guide-fingers extended beyond its open end, a piston in said port adapted to traverse said fingers, a valve within said casing, and means connecting said valve and piston for simultaneous movement, substantially as specified.

7. A relief-valve comprising a casing having a valve seat or pocket and an enlarged path or way therein, a flap-valve curved in cross-section and pivoted within the casing to travel in said path and to lie within said seat, a relief-port from the casing, and means controlled by said valve for opening and closing said port, substantially as specified.

S. A relief-valve comprising a casing provided with a curved seat in its wall and a curved path, a flap-valve pivoted in said casing and having a curved body to conform to said seat and a curved end to conform to said path, and means for operating said valve; substantially as specified.

In testimony whereof I afiix my signature in presence of two witnesses.

MAURICE D. LARKIN.

Witnesses:

EDWARD GEISLER, PAUL DALY. 

